We have evidence from different studies all over the world
Answer:
Most people experience increased infant mortalities at high altitudes due to the inability of the mother to provide sufficient oxygen to the developing fetus but now variation in the DNA sequence in the people that lives at higher altitudes like in Tibetans allow normal level of infant survival at high altitudes.
This variation occurred in the EPAS1 gene in the Tibetan population that is responsible for delivering oxygen more efficiently to the fetus. This nucleotide variation is also present in low landers of Beijing but natural selection selected the variant gene in Tibetan people because they require this mutated gene for their survival.
So the population passed this variant gene in next-generation, therefore, inheritance allowed the spreading of the mutated gene to the next generation therefore by natural selection and inheritance a mutated gene spread through a human population that had just begun living high in the mountains.
Biotic factors are living things within an ecosystem; such as plants, animals, and bacteria, while abiotic are non-living components; such as water, soil and atmosphere.
So to answer your question,
Biotic: plants and other prey (animals)
Abiotic: water, soil,
Hope this helps!
